In an aircraft, especially commercial aircraft, there is a minimum configuration of equipment that is required to be operational for the aircraft to depart. For attitude instrumentation (which provide aircraft pitch and roll indications) the current state of the art requires some aircraft types to have two primary attitude sources and a secondary attitude source in order for the aircraft to depart. Attitude measurements from the two primary attitude sources are displayed on the primary display system, which includes separate screens for both the pilot and the co-pilot. The secondary, or standby, attitude source is displayed on a standby display system. The reason three total systems are required to be operable prior to takeoff is so that misleading information can be readily identified. That is, if one of the attitude sources starts presenting misleading information while the aircraft is in flight, the other two sources should still be in agreement so that the misleading source is quickly identified. If any of the three attitude sources are failed prior to departure, the aircraft cannot depart and the aircraft operator (such as an airline, for example) will incur significant costs to delay or cancel the flight until the aircraft can be brought up to minimum configuration. To avoid incurring these expenses, airlines could maintain significant and distributed pools of spare attitude instrumentation devices, so that a replacement device can quickly be installed and the aircraft returned to an operation configuration. The cost of maintaining these pools, while less than the costs of cancellation or delay, are still very significant.
For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for alternate systems and methods for isolating attitude failures in aircraft with minimum equipment list configurations.